The Panel of Hands, El Castillo cave, Spain. A hand stencil has been dated to earlier than 37,300 years ago and a red disk to earlier than 40,600 years ago, making them the oldest cave paintings in Europe. A study in Science finds that cave art in Spain is even older than we thought. (Pedro Saura / AFP/Getty Images)
A closer look at the Panel of Hands, El Castillo cave, Spain. (Pedro Saura / AFP/Getty Images)
The famous polychrome ceiling of Altamira cave, Spain. The double “claviform” symbol (top right) has been dated to earlier than 35,600 years ago, making it some 20,000 years older than the polychrome bison in the background. (Pedro Saura / AFP/Getty Images)
Paintings of horses at the Tito Bustillo cave, Spain. These overlay earlier red paintings that, based on uranium-series dating elsewhere in the cave, might be older than 29,000 years. (Rodrigo De Balbin Behrmann / AFP/Getty Images)
Another look at the hand stencils at the El Castillo cave in Spain. (Pedro Saura / AFP/Getty Images)
